A succession of brutal murders of women and children in South Africa has sparked national outrage and calls for action to end persistent violence.

"We, as the citizens of this country, we must say enough is enough," said South African President Jacob Zuma, speaking Thursday at a service for three-year-old rape and murder victim Courtney Pieters of Cape Town. "This cannot be accepted. The police must double their effort. I don't know whether we need to introduce more harsher laws or change the laws. This, I think, we must discuss. It's a crisis in the country."

South Africa has long had high levels of rape and murder, but a rash of crimes in recent weeks has grabbed national attention.

The remains of 22-year-old Karabo Mokoena were buried Friday. Her charred body was found this month at an illegal dump in Johannesburg. Her boyfriend, who police say confessed to killing her, has been arrested.

Well-known South African men have stepped up, calling on other men to take a stand.

"When are we going to take our position in society, in families and come to the defense of our women and children?" said actor Patrick Shai. "When is that? How many Karabo's must be dead before you stand up as a man and say it will not happen in my name?"

Karabo's death was followed by the gruesome killings of four other women, also in Soweto, the southwestern suburb of Johannesburg. Two of the women were friends. Three suspects have been arrested in connection with their case. The other two cases are being investigated separately.

Police say all four women appeared to have been raped and murdered.

The youngest victim, Nombuyiselo Nombewu, was 15 years old. Her aunt, Vuyelwa Nombewu, says she cannot understand why someone would do this.

"There is a lot that we expected from Nombuyiselo. We never thought her life will end this way," Nombewu said.

The crimes of aggravated murder and rape in South Africa carry sentences of 25 years in prison. While Zuma says harsher penalties may be needed, activists say police are not aggressively enforcing the existing laws.

Police Minister Fikile Mbalula accepts the criticism.

"Some cases have been reported, including to the police," Mbalula said. "Not enough action has been taken. Now is the time to amplify and speak to those who passed on and those who are still alive to have a massive campaign on the question of gender-based violence."

Cheryl Tshabangu of the Pink Ladies Organization, a group in South Africa that helps trace missing children and family members, says it is important that education starts young.

"It's high time we taught a boy child what it means to respect a woman," Tshabangu said. "We are living in societies that are broken. Most of these boys who end up being abusive are growing up watching the abuse happening at home."

One in five women in South Africa experience violence at the hands of a partner, according to a study released last week by the government agency Statistics South Africa.